Corrosion-resisting ferrous alloy



Patented Sept. 9, 1924.

UNITED STATES PATENT OFFICE.

WILLIAM H. SMITH, OF CLEVELAND, OHIO, ASSIGNOR TO LUDLUM STEEL 00., F

WATERVLIET, NEW YORK. A CORPORATION OF NEW JERSEY.

CORROSION-RESISTING FERROUS ALLOY.

Ho Drawing.

To all whom it may concern:

Be it known that I, WILLIAM H. SMITH, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Corrosion-Re sisting Ferrous Alloys, of which the following is a full, clear, and exact description.

This invention relates to a metal alloy which has inherent in it, certain qualities and characteristics that make it exceedingly useful and desirable for use under circumstances which require an article to be resistant to corrosive action of other metals,

liquids, solids, fumes or gases, or where the metal object or part is repeatedly heated to high temperatures, and a non-warping, non-cracking structure is desirable, or

where the object or part is subjected to heavy service which occasions wear and tear.

The alloy comprises a combination of chromium, iron, titanium and manganese, and; silicon or aluminum, or both. silicon and aluminum, present in small quantities.

In melting the alloy, ferro-chrome is preferably used, and in order to produce the alloy at low cost, the ferro-chrome produced by the electric furnace process may be used, but ferro-chrome produced by the thermite or other processes may be used if desired.

The alloy comprises substantially 15 to 40 per cent chromium, .04 of 1 per cent to 12 per cent (the titanium with manganese being .54 to 14 per cent) .5 per cent to 3 per cent of silicon, the balance consisting mainly of iron and carbon. Aluminum may be present in small amounts, for instance, .04 of 1 per cent to 3 per cent.

As an example of a typical analysis of an alloy found to have the desirable qualities, the following is given: 18 per cent chromium, 1.5 per cent manganese, 1 per cent silicon, .20 to .35 r cent titanium, .03 per cent aluminum, p osphorus and sulphur less than .05 per cent, balance iron and carbon.

The silicon and aluminum (if the latter be added are added just before the metal is poured, t ese elements acting as de-oxidizers for the metal bath, .and also imparting: fluidity to the metal so that it may be Application filed February 27, 1919. Serial No. 279,650.

poured readily. Furthermore these metals or metalloids, of either or both of which the alloy may contain about .54 per cent to 6 per cent, apparently form a skin coating or film of oxide which is non-flaking, and pro- ;ects the metal from further oxldizing efsets.

The titanium acts in part as a scavenger and de-oxidizer, and in part apparentl combines with the nitro en that may occluded in the molten alloy, apparently forming a compound of nitrogen and titanium, which is taken up by the slag. Any additional titanium which is in excess of that removed with the sla appears in the final alloy and imparts to t 1e alloy the properties of toughness, resiliency and resistance to cracking. The quantity of titanium may be varied, in accordance with the degree in which it is desired to dproduce the characteristics just mentione The alloy is referably produced in the electric furnace y melting ferro-chrome together with the various other ingredients of the alloy which have been mentioned, and with a suitable flux such as is well known in the art. In making the alloy it is only necessary to bring the temperature of the furnace to the point necessary to produce a complete melting and then incorporatin the various elements of the alloy. It has een found that when the alloy "contains a low percentage of carbon it is fairly malleable, and where the carbon is kept as low as about .07 per cent to .08 per cent, the alloy is also easil machinable. In many circumstances t is quality of malleability is important and desirable.

Having described my invention, claim:

1. A substantially nickel free alloy containin at least of iron, not less than 15% o chromium, 04% to 12% of titanium, and an appreciable quantity of manganese not in excess of 2%.

2. An alloy containing gradients iron, chromium and titanium, and containing chromium 15% to 40%, an appreciable quantity of titanium not in excess of 12%, and an appreciable quantity of manganese not in excess of 2%.

3. An alloy containing as essentlal ingredients, substantially 15 to 40 per cent of chromium, substantially 4/100 of 1 per cent as its principal in- 18%, manganese about 1.5%,

to 12 per cent of titanium, an appreciable quantity of manganese not in excess of 2%, and the balance of iron and carbon.

4. A ferrous alloy consisting of tially 15 to per cent of chromium, 4/100 of 1 per cent to 12 per cent titanium, of 1 per cent to 2 per cent manganese, of per cent to 3 per cent silicon, and 4/100 of 1 per cent to 3 per cent of aluminum.

5. An alloy containing substantiallylS per cent chromium, 3/10 per cent titanium, 1 per cent manganese, per cent silicon, balance iron and carbon.

6. Alloyed malleable soft steel resistant to corrosion and to oxidation at elevated temperatures and containing substantially chromium 15% to 40%, titanium with manganese .54% to 14%, and material having the protective film forming properties of silicon and aluminum .54% to 6%.

7. Alloyed malleable soft steel resistant to corrosion and to oxidation at elevated temperatures and containing chromium 15% to 40%, titanium with manganese .5472; to 14%, and silicon .5% to 3%.

8. Alloyed malleable soft steel resistant. to corrosion and to oxidation at elevated temperatures and containing chromium about 18%, manganese about 1.5%, silicon about .5% to 3%, titanium about 20% to 35%, and aluminum about 03%.

9. Alloyed malleable soft steel resistant to corrosion and to oxidation at elevated temperatures and containing chromium about material havsubstaning the protective film forming properties of silicon and aluminum about .54% to 6%, and titanium about .2070 to 35%.

10. Alloyed malleable soft steel resistant to corrosion and to oxidation at elevated temperatures and containing chromium about 18%, manganese with titanium about .54% to 14%, and material having the protective film forming properties of silicon and aluminum about 54% to 6%.

11. Alloy resistant to corrosion and to oxidation at elevated temperatures and contain ing chromium 15% to 40%, titanium with manganese .54% to 14%, material having the protective film forming properties of silicon and aluminum .54% to 6%, and the principal part of the remainder iron.

12. Alloy resistant to corrosion and to oxidation at elevated temperatures, containing substantially chromium 15% to 40%, manganese about to 2%, titanium about 04% to 12%, material having the protective film forming properties of silicon and aluminum about .54% to 6%, and the principal art of the remainder iron.

13. Alloy resistant to corrosion and to oxidation at elevated temperatures and containing substantially chromium 15% to 40%, manganese about .50% to 2%, titanium about .04% to 12%, and silicon about .5% to 3%, and the principal part of the remainder iron.

In testimony whereof, I hereunto aflix my signature.

WILLIAM H. SMITH.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,508,032, ranted September 9, 1924, upon the application of \Villiam H. Smith, of Cleve nd, Ohio, for an improvement in Corrosion-Resisting Ferrous Alloys, an error appears in the printed specification requiring correction'as follows: Page 1, line 35, after the word .cent insert the following words titanium, .5 to 2 per cent wumganmse; and that the said Letters Patent should be read with this 'oormction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed aml sealed this 14th day of October,'A. D; 1924.

[an/uh] KARL FENNING,

' Acting Commissioner of Patents. 

